When Jason Alexander first signed up to play the title character, he thought he signed up for a one-off role. Because of this, he thought it would be fine to give Duckman a voice very different from his. While he loved doing the show, he reportedly came very close to damaging his voice; and because of this, he didn't reprise his role in the 1997 PC Adventure game.
Most of season four's episodes featured musical numbers to capitalize on Jason Alexander's Broadway success.
The series premiered the same year as another Klasky Csupo production, Aaahh!!! Real Monsters (1994).
When Dana Hill passed away in 1996 the role of Charles was recast. The role of Charles was given to Pat Musick.
Cornfed's deadpan, Joe Friday-esque voice came about as a happy accident. Voice actor Gregg Berger was not able to be with the rest of the cast during the initial recording sessions for the first half of the first season, as he was in Russian filming Police Academy: Mission to Moscow (1994) so had to record his lines over the phone, resulting in very his character's deadpan delivery, which the producers fell in love with.